The present invention relates to a method of manufacturing printed circuits, particularly with fine conductive paths.
Methods of manufacturing of printed circuits are known in the art. Known methods possess some disadvantages which will be described hereinbelow. The so-called subtraction method possesses the disadvantage in the fact that the great quantity of the coating of the base material must be removed after the formation of the conductor pattern. At the same time the etching of the conductor train takes place with the accompanied deterioration which becomes more serious and extensive with the speed corresponding to the reduction of the width of the conductor paths. This phenomena prevent a further miniaturization within the frame of the subtraction method.
The so-called addition method has the disadvantage in the fact that the material can also deposit more or less on the insulating surfaces in undesirable manner. An additional disadvantage of this method is that the entire plate coated with an adhesive agent must be chemically treated. Because of this intensive moisture treatment, the adhesive agent has an electric insulating value which is considerably smaller than that of the epoxy resin, which also put the miniaturized printed circuits within narrow limits.